The present invention relates to medicament delivery devices such as automatic injection devices for injecting liquid medicament with a needle in a patient and nebulisers for administering a medicament in the form of a mist to be inhaled into the lungs of a patient.
Auto-injectors, or pen-injectors have been on the market for many years. During recent years some medicaments have been developed to be injected by patients themselves. Therefore, depending on the intended use and type of medicament, there have also been developed injection devices having a varying degree of automatic functions to facilitate the injection of medicaments in a reliable and safe way for patients and even for trained personnel; e.g. physicians and nurses.
WO 2012/173553 discloses an injection device comprising a housing and a container holder arranged within the housing. The container holder is configured for accommodating a medicament container having a needle attached to one end thereof and a stopper sealingly and slidable arranged inside the medicament container at the other end thereof. A plunger rod is arranged with a proximal end thereof contactable with the stopper. A first and a second energy accumulating member is arranged in the interior of the housing of the injection device and adapted to accumulate and store energy. A plunger drive means is slidably arranged in relation to the plunger rod, is rotationally locked to the plunger rod, and is rotatable in relation to the housing. The plunger drive means is operationally associated with the first energy accumulating member. A container driver is arranged for being connectable to the container holder and is threadedly connected to the plunger rod. The container driver is operationally associated with the second energy accumulating member such that due to an output axial force from the second energy accumulating member, the container holder and the plunger rod are axially moveable in relation to the housing a predetermined distance towards the proximal end of the injection device from an initial locked position to a second position whereby a needle penetration is performed. The plunger drive means is locked from being rotated by the container driver. The plunger drive means is released such that due to an output torque from the first energy accumulating member the plunger drive means is allowed to be rotated and the plunger rod is urged towards the proximal end of the injection device whereby an injection is performed.
Some medicaments administered via medicament delivery devices comprise two medicament components, which require mixing before being administered via a relevant medicament delivery device such as an injection device or a nebuliser.
In the context of a piston rod drive system for a manually operable drug delivery device WO 2012/085208 discloses a piston rod drive system comprising a main body adapted for coupling with a reservoir. A user operable activation element is operatively coupled with the main body and configured to move axially and rotationally relative to the main body between a first position and a second position to transfer a solvent from a rear chamber of a cartridge to a front chamber thereof. A piston rod element is operatively coupled with the activation element and the main body and configured to move axially and non-rotationally relative to the main body in response to the activation element being moved between the first position and the second position. The piston rod drive system and the drug delivery device as such do not lend themselves to be automated.
There exists a need for a medicament delivery device, which provides for an automated mixing of two medicament components.